From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 80CC251DAFE; Wed, 30 Sep 2026 18:24:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792651; cv=none; b=IRd/h+QBLPXsVEL5f1pPVG3/nh3IBETxT9pNq3AGqLiFC+CP3jvou4ggD2UhpWH+mo15uCmiNSY0o5FuSVzFRwzxEqDZID/lsQ2p4uK3WMzgufbs3MCETQd9QCsoSj0hIQKNLbWW498HS7qTXdh00N5sDiLAEgcgjbkoDCDU1Dg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790792651; c=relaxed/simple; bh=WVFjh7OfgXSbolrxcqmmUpVbkbLI0Tk+mckhBKYj9Q0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KrJfHCBjXInbnBsV3agA0B1zJOztAnDjxt6i8hPv6+VDHn2vYwNhx8rrUtpZJZN2zAhy6PtV8JCGPrEVZVgPPvlrDQXJYiNrbrYjdrzlC0VuueCfYvjMHy0Dl/OfRFWGVyC/lnYjlp+ZqbdH6+OQaxfxYRbnDEAG3iR6ISzany8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Cfo1zx/u; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Cfo1zx/u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A1031F00899; Wed, 30 Sep 2026 18:24:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790792650; bh=pko7/HF/bOfSwCaYJj0OjadibP4SV342j7N7RkzDX7g=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Cfo1zx/uUAp9REweemGvNKaHwB0REcRsAi83yOrjVMkEuKCjnKgZJMkInPoFOjzVt gyHR6o5J1iNqRlWuP/2G8zIRmeN9EbmMXWWKLIuOqeYXVEIrHR0giX/ARwmVW8VHBF AQCkMtmBl3DFJbZ6eQ0Eb1i46qCKy0XpC7z9iYyA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yehyeong Lee , Mike Christie , "Martin K. Petersen (Oracle)" Subject: [PATCH 5.15 730/752] scsi: libiscsi_tcp: Check the data direction of a Data-In PDU Date: Wed, 30 Sep 2026 17:30:00 +0200 Message-ID: <20260930152414.013210833@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152358.131179731@linuxfoundation.org> References: <20260930152358.131179731@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yehyeong Lee commit bce07e2f37b5e4a427d36fd6b1c14067b27591db upstream. The Data-In branch of iscsi_tcp_hdr_dissect() resolves the ITT to a task and copies the PDU's data segment into that command's scatterlist without asking whether the command was reading. iscsi_tcp_r2t_rsp() in the same file does ask, and rejects an R2T for a command that is not DMA_TO_DEVICE. A target that answers a WRITE command's ITT with a Data-In therefore has the initiator write target-supplied bytes into the pages that write was about to send. Those are the caller's own pinned pages for an O_DIRECT write, and page cache pages for a buffered one. Observed against a test target that emits one 512-byte Data-In naming a 128 KB write's ITT, after the R2T for that write. With O_DIRECT the caller's buffer ends up holding 512 bytes of the target's data while pwrite() returns 131072. Buffered is quieter: pwrite() and fsync() both succeed, nothing is logged, and reading those blocks back returns the target's bytes out of the page cache without a command going on the wire. Check the direction before using the scatterlist, the way the R2T path already does. Cc: stable@vger.kernel.org Signed-off-by: Yehyeong Lee Reviewed-by: Mike Christie Link: https://patch.msgid.link/20260801133635.1986706-1-yhlee@isslab.korea.ac.kr Fixes: a081c13e39b5 ("[SCSI] iscsi_tcp: split module into lib and lld") Signed-off-by: Martin K. Petersen (Oracle) Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/libiscsi_tcp.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/scsi/libiscsi_tcp.c +++ b/drivers/scsi/libiscsi_tcp.c @@ -491,6 +491,9 @@ static int iscsi_tcp_data_in(struct iscs int datasn = be32_to_cpu(rhdr->datasn); unsigned total_in_length = task->sc->sdb.length; + if (task->sc->sc_data_direction != DMA_FROM_DEVICE) + return ISCSI_ERR_PROTO; + /* * lib iscsi will update this in the completion handling if there * is status.